Tube forming mill



July 22, 1969 I G. F. BALFANZ, JR 3,456,472

TUBE FORMING MILL Filed Nov. 22, 1966 4 Sheets-Sheet 1 (\I 3* w A H o (\1 g LL 3 ...1 LL m m II) J r r 8 Inventor Glenn F. Bulfonz, Jr.

Attorney July 22, 1969 BALFANZ, JR I 3,456,472

TUBE FORMING MILL Filed Nov. 22. 1966 m 4 Shets-Sheet 3 O (\1 ID .1

FIG. 4

Inventor Glenn F. Bo|tc|nz-,Jr.

ByV r KM Attorney Jul 22, 1969 G. F. BALFANZ, JR 3,456,472

TUBE FORMING MILL Filed NOV. 22, 1966 4 Sheeis-Sheet 4 Inventor Glenn F Boljcnz, Jr. By 1 4 A/MQL Attorney United States Patent ABSTRACT OF THE DISCLOSURE I A tube forming apparatus in which the construction of the roller assemblies and the mounting and the drive thereof'function to accurately initially bend aflat strip of rnaterial'to form quarter circle lateraledge' sections and reversely bent center section and then bend the center section outwardly to close in the lateral sections to obtain a 90 butt seam and wherein the roller assemblies are accurately adjustable axially and radially to hold the forming tube from turning and taut and to maintain its seam upright while it is advanced through the welding station. I, 7 r

This invention relates to a forming mill and more specifically to a mill for making tubes from extremely thin stock for surgical needles and the like although not specifically restricted thereto.

In structures of the type under consideration in which a strip of material is fed through the mill, difliculty is experienced in shaping the strip so as to eliminate distortion or twisting. Various roller combinations have been used to progressively shape the strip into tubular form. Wear of the roller profiles together with difiiculty of adjustment of the roller pairs has limited the productivity of the apparatus and enormously increases the cost of the end product. f f The invention comprehends a mill construction having rollers of novel contours in various stations of the mill wherein the strip is formed in predetermined cross-sections such that the free lateral edges of the. strip obtain anoptimum relation to each other preparatory to welding such thatiupon these edges being welded, the tube is round and does not require grinding or other expensive and frequently ineffective operations.

A further object of the invention is to provide a novel mounting for the forming rollers which'permits accurate alignment in a facile manner.

Another objectof the invention is to provide a novel roller arrangementandadjustments, therefor, such that byproper adjustment, twisting of the tube, in theQfo-rmation thereof iseliminated and theproper shaping is main- 3,456,472 Patented July 22, 1969 form without the necessity of reshaping these sections internally.

These and other objects and advantages inherent in the invention will become more readily apparent from the specifications and the drawings, wherein:

FIGURE 1 is a plan view of the novel forming mill;

FIGURE-2 is a diagrammatic side elevation of the structure of FIGURE 1 showing the roller relationship;

FIGURE 3 is an enlarged side elevational view of one of the roller stations; taken generally on the line 3-3 of FIGURE 1;

FIGURE 4 is a cross-sectional view taken substantially on M11044 of FIGURE 3;

FIGURE 5 is a cross-sectional view taken substantially on line 5-5 of FIGURE 4;

FIGURE 6 is an enlarged side elevational view of another roller station taken substantially on 1ine.6-6 of FIGURE 1;

FIGURE 7 is a cross-sectional view taken substantially on line 77 of FIGURE 6; 4

FIGURE 8 is a cross-sectional view taken substantially on line 8-8 of FIGURE 7; and

FIGURES 9a, 9b, and 10 through are fragmentary edge elevational views of the rollers of the respective stations from left to right of FIGURES 1 and 2.

DESCRIPTION OF THE INVENTION a The tube forming mill generally designated 20 comprises a suitable base 21 supporting a plurality of roller stations identified 1 through 12.

These stations are powered from a motor 22 which is coupled through gearing diagrammatically shown at 23 to an input shaft assembly 24 which includes flexible couplings 25, 25 interconnecting line shaft lengths 26, 26.

These shaft lengths 26, 26 extend through boxes 28, 28 of the respective roller assemblies as best seen in FIG- URES 5 and 6.

Each gear box 28 comprises a housing suitably mounted on the base 21 and having a pair of laterally spaced upright side walls 31, 32 supporting aligned sealed bearing assemblies 33, 34 which journal opposite ends of a hollow shaft or quill 35 formed integral with a worm 36.

The end portions 37, 38 of the quill 35 extend outwardly of the respective side walls of the associated gear box and are slotted at 39, 40 and are encompassed by split securing collars 41, 42 which are tightened about the respective end portions by means of screws 43, 44

-. extending across the split and threaded into the adjacent tained at each stage irrespective of the wear of the rollers.

A further object is to provide a simple and effective roller mounting which positively precludes end 'play which results in scuffing of the material and undesirable deformation in addition to lack of'control of the twist of the tune. i

- Another object is to devise. a novel mill comprising tion are being made slightly larger than that required in l the final form of the tube so that upon bending the'central portlon outwardly in the later stages, the lateral portions fold toward each other in a naturally developing tube portions of the collar. The respective end portions of the quill are thus drawn against the related shaft section 26 extending therethrough. This feature permits placement of the gear boxes 28 along the length of the respective shaft section 26 in optimum position with respect to the related roller station. The worm 36 meshes with a worm gear 45 which is keyed as at 46 to a horizontally extending output shaft 47 which is journaled in bearings 48, '49 mounted upon walls 50, 51 of the related gear box. Shaft 47 is connected to a hub section 52 of a flexible friction clutch coupling 53 which includes a nylon chain 54 which engages teeth 55 on hub 52 and the teeth of a sprocket plate 56 which is sleeved onto a hub 58 which is keyed as at 59' onto an output shaft 59. The sprocket 56 is embraced between a pair of friction disks 60, 61 also sleeved on hub 58, disk abutting a collar 62 on hub 58 and disk 61 being engaged by a plate washer 63 which is engaged by a Belleville spring 64, the spring 64 being adjustable by a nut 65 which is threaded as at 66 on the hub 58 to vary the pressure of the plates with the sprocket 56 which with disks 60, 61 forms a clutch. Shaft 59 extends through a seal 67 which has a mounting bracket 68 suitably bolted onto a frame 69 of an associated station. Shaft 59 has a pair of axially spaced enlarged portions 71, 72 which extend respectively through the inner races 73, 74 of bearings 75, 76. The bearings and shaft 59 extend through a bore 77 in frame 69 and the outer race 77 of bearing fits snugly into a counterbore 78 and at its inner edge 79 seats against a shoulder 80 at the inner end of counterbore 78. The outer edge 81 of the inner race 73 is engaged by a washer 82 which is drawn up against the inner race by a nut 84 threaded onto a portion 85 of shaft 59.

The inner race 74 of bearing 76 has its outer edge 86 seated against a shoulder 87 formed on the inner end of an enlarged portion 88 formed on shaft 59 adjacent to its outer end and the outer race 89 of bearing 76 snugly fits into a counterbore 90 and has its inner edge seated as at 91 against the shoulder 92.

Thus tightening of the nut 84 holds the bearings 75, 76 in place without end play of shaft 59.

A seal 93 is sleeved over shaft portion 88, the seal being mounted in a holder 94 which is suitably bolted to the frame 69.

The outer end portion 99 of the shaft 59 is of reduced diameter and mounts a lower first forming female roller 1L between the enlarged portion 88 and a nut 101 threaded on the end portion 99 and tightly drawing the roller 1L, which has a center bore closely fitting the unthreaded part of shaft portion 99, between a washer 102 and outer edge of portion 88. Thus shaft 59 and roller 1L rotates as a unit.

The lower roller 1L of the preforming station cooperates with an upper roller 1U which is mounted on a reduced diameter outer end portion 103 of an idler shaft 104, the roller 1U being tightly clamped between a nut and washer assembly 105 on the outer threaded end portion 103 and an enlarged portion 106 of shaft 104. This enlarged portion 106 has an intermediate section 108 of even larger diameter than portion 106 and portion 106 has an axial extent longer than the thickness of the seal assembly 109 sleeved thereon. The seal assembly 119 is suitably bolted to a mounting block 69a.

The inner edge 110 of portion 106 forms a shoulder for the outer edge of the inner race 111 of a bearing assembly generally designated 112. The bearing assembly 112 includes conical rollers 113 nested between the inner race 111 and an outer race 114 which is snugly fitted into a counterbore portion 115 of a holder or carrier 116 which fits complementally into a bore 117 in the block 69a. The shaft 104 extends through the bore 118 in the tubular sleeve or holder 116 and at its inner end has an enlarged portion 119 of the diameter of portion 106, said portion 119 mounting the inner race 120 of a bearing assembly generally designated 121. The bearing assembly 121 includes conical rollers 122 disposed between the inner race 120 and an outer race 123 which fits snugly into a counterbore 124 in sleeve 116. The inner end 125 of shaft 104 is threaded and receives a washer in abutment with the inner race 120 and a nut is threaded thereon and holds the bearings and shaft 104 in assembly with the sleeve holder 116 against axial movement. Thus the entire assembly including roller 1U is held as a unit with the mounting sleeve and are movable axially only with the sleeve.

The sleeve or holder 116 has an inner end externally threaded portion 127 on which is threaded a locking nut 128 which upon adjustment of the holder 116 is drawn up tight against the face 129 on the block 69a. The distal end of the sleeve 116 is provided with a wrench-engaging polygonal portion 130 for rotation by a tool. The sleeve is threaded internally as at 131 and has a sealing cap 132 threaded thereinto.

The novel mounting of the roller 1U permits extremely accurate adjustments of the roller 1U with respect to roller lL-since the shafts are mounted parallel and held so by the structure hereinbefore described.

The block 69a is movable, vertically, on two pairs, front and rear, of vertical tie rods 133 which extend through vertical bores 134 in block 69a.' These tie rods abut at a shoulder at 136 against the upper surface 138 of frame 69 and at a shoulder at the undersurface 139 of a mounting plate 140. The lower end of the tie rod extends through vertical bores 144 in the frame 69 and its base plate 146 which is bolted as by bolts 147 to the main machine base 148 and aligned thereon with a register key and slot arrangement designated 149. The upper and lower ends'of the tie rods have threaded lengths which are provided with lock washer and nut assemblies 142 which clamp the frame 69 and its base plate 146 together at the lower end of the tie rod 133, and also secure the mounting plate and gear housing 150 together at the upper end of the tie rod 133. The tie rods 133. together with the'lock washer and nut assemblies 142 thereby provide a simultaneous meansof accurate alignment or assembly location for, while securing, the frame 69, block 69a, mounting plate 140, gear housing 150, and the base plate 146 together as a unitized assembly.

A, hand crank operated-adjusting screw assembly '151 is mounted in the housing 150 and is connected to the block 69a for moving the same vertically on the tie rods 133. Thus the roller 100a is adjustable toward and away with respect to roller 100 to provide a spacing in accordance with the thickness of the material entered therebetween.

Stations 1, 2, 3, 4,7 and 9, 10 and 12 are identical except for the shape of the profiles of the rollers and these are all driven as best seen in FIGURE 1.

The horizontal roller stations 5, 6, 8, and 11 are identical except for the roller profiles and the rollers thereof are all idlers, that is, they are not driven. Station8 is depicted specifically in FIGURES 6-8 and comprises a base which is bolted as at 176 to the support platform 21. The base 175 has a horizontal dovetail slot 177 which extends transversely of the forming tube. This slot 177 complementally admits a T-shaped interlocking guide portion 178 of cradle 179 which has wing portions 180, 180 which, with the horizontal flanges 181, 181 on block 32, embrace the reentrant flanges 182, 1 82 on the base This cradle is adjusted by means of screw assemblies 183, 184 which are mounted on upturned flanges 185, 186. Assembly 183 abuts end 183' and assembly 184 having a screw portion 187 threaded into the end portion 188 of cradle 178. It will be apparent that upon releasing the locking nuts 189, 190 the screw assemblies may be retrgcted or advanced as desired and then the nuts tightene The cradle 179 has an upwardly open pocket 192 in ts upper srde which admits a pair of associated roller assemblies, which in FIGURES 6-8 includefrollers 8HL and 8HR which are mounted on vertical shafts 193, 194, the lower ends 195, 196 of which are threaded into vertlrggl threaded bores 197, 198' in mounting blocks 198,

The rollers 8HR, 8HL are mounted. on bearings 200,

of the rollers 8HL, 8HR in a horizontal planeto effect horizontal alignment. The shafts 193, 194 are secured in adjusted position by split clamp assemblies 212, 213' which are secured to the respective block by a screw 214 (FIGURE 8) and embrace the respective shaft such as well seen in FIGURE 6 wherein the horizontal adjustment screw 215 is embraced by a split clamp 216 which is secured by screw 217 to a flange 218 defining one end of pocket 192 in cradle 179, the clamp being tightened or loosened by grasping a handle 220 and rotating the shaft 222 which is threaded through a leg 223 of the clamp and extends through opening 224 in leg 225 and abuts the external side of such leg with a shoulder 226a.

The screw 215 has leftand right-hand thread portions at 226, 227 which thread into correspondingly threaded bores 228, 229. The end 230 of the screw 217 is journaled by a bushing in a flange 230a of the cradle 179.

The mounting blocks 198, 199 each have oppositely I intruding horizontal flanges 231, 232 which fit accurately into slots 233, 234 on the side Walls 235, 236 of the cradle 179. By turning the screw 215 the blocks and their rollers SHL, SHR are adjusted to and fro to adjust the gap 238 therebetween.

At the intake side of the rollers '8HL, 8HR, there are provided vertically spaced guide rollers 240, 241 adjustable vertically relative to each other and to the rollers SHL, SHR on a vertical standard 250 by loosening the shafts 240a, 241a which mount the rollers 240, 241 and positioning and tightening these shafts with their rollers vertically in slot 242 until the gap 243- defined therebetween is properly aligned with the related rollers and properly feeds the forming tube strip into these rollers.

It will be noted that the flat metal strip 245 feeds off a drum, not shown, across the guide rollers 246 into station 1 which includes the forming rollers 1L, 1U, these being shown in profile in FIGURES 9a, 9b.

The lower roller IL is the female roller'and 1U the male roller. The female roller IL is provided with an outwardly convexed center profile 250 which merges at opposite sides of the roller into concave codimensional grooves 251, 252. These grooves terminate in annular ridges 253, 254 which are in a common plane with the crest of curvature indicated at 255 of the profile portion 250. The ridges 253, 254 are flanked lby radial flanges 255, 256 which define opposite sides of roller 1L and provide interior guide surfaces 257, 258 which are normal to the axis of the rollers 1L. Thus the strip 245, which is of width substantially exactly that of the distance between the surfaces 257, 258, is centered on the roller.

The upper roller 1U has a profile complementary to the lower roller in having a pair of raised annuli 259, 260 with edge surfaces 261, 262 complementary to groove surfaces 251, 252 and in exact vertical alignment with the respective thereof and spaced minutely less than the thickness of the strip entered therebetween. Thus the strip is initially bent to provide an upward bulge 264 centered intermediate its lateral edges 265, 266 and between the portion 264 and the edges 265, 266 is formed with reversely or downwardly convexed portions 267, 268. This is termed a reverse bend operation. The roller 1U is relieved at 269' between the rings 259, 260 to accommodate the upwardly convexed portion 250 of the lower roller and the upwardly convexed center portion 264 of the strip. FIGURE 9a shows the position of the strip preparatory to deformation showing the bottom surface 270 of the strip laying flat across the crest 255 of the center porrequirements. Correspondingly the profiles of the rings 270, 271 on the periphery of roller 2U are deeper than 1U.

The radium of curvature of the convex portion 264 in roller IL is twice that of roller 2L and the radius of the curvature of the convexity 264 in roller 2L is equal to diameter of the tube at the bend line minus one-half the stock thickness.

The first two stations form the edge portions 267, 268 into quarter circles (90") by overbending to 100 to take care of spring back.

The strip then passes through station number 3 wherein the lower roller 3L is formed with a peripheral groove 273 of substantially a 120 angle and the upper roller 3U is provided witha single central annulus which has a contour 274 complementary to that of groove surface 273 and of a width substantially equal to the width of the center portion 264a. Thus the strip'is reversely bent thus forcing the two preformed quarter circle portions 267, 268 to close in and begin to form a circle.

Station 4 further closes the lateral portions 267, 268 and the peripheral groove 275 in roller 4L has an included angle of substantially 110 and the upper roller has an annulus 276 with a peripheral surface 277 complemental to surface 275. The width of the annulus 276 is p less than the space S between the edges 278, 279 of the lateral portions when these are bent up.

The next station 5 has horizontal rolls SHR and 5HL with concentric grooves 280, 281 of the same radius and these rollers engage the external sides of the lateral portions and squeeze them into an open circle of a diameter of the space between these rollers.

The tube is further squeezed horizontally by passing between rollers 6HL and 6HR within grooves 282, 283

which are of a lesser diameter than grooves 280, 281 and spaced closer.

The forming tube is passed to rollers 7L, 7U of station 7 wherein the roller 7L has a groove 285 which is of a radius approximately that of either of the grooves 282, 283 and the upper roller 7U is provided with a complementary groove 286 which is interrupted centrally by tion of the roller 1L and surfaces 253', 254' on the ridges v FIGURE 9b shows the strip deformed whereby the lateral dimension of the strip is reduced such that the lateral portions 267, 268 slide oif the ridge surfaces.

The strip feeds into the reverse bend station 2 whereat the'rollers 2L, 2U further deform the strip. Female roller 2L has a central convex profile of an included angle of about 80 and the concavities at opposite sides of the roller are each about 100". Thus in cross-section the strip is deformed into a form having sinusoidal profile. In roller 1L, the depth of the grooves or concavities 251, 252 is about half of the depth of the grooves or concavities 251a, 252a in roller 2L, which has a radius about .005 inch larger than the final tube dimension, for sizing a seam guide disk 287 which has a width approximately the space at that station between the lateral edges of the tube and serves to maintain the seam at the top.

Station 8 has rollers '8HR and 8HL embracing opposite sides of the forming tube and has grooves 288, 289 approaching the final diameter of the tube.

Station 9 is similar to station 7 however the radii of the grooves 290, 291 of rollers 9L, 9U is lesser than station 8 grooves and the seam guide disk 292 is thinner than disk 287.

The tube passes from station 9 to a welding station 294 whereat the seam edges of the tube are welded and the tube emerges from the station or weld box 294 into roller station 10 housing rollers 10U, 1'0L which engage I the upper and lower sides of the tube and have grooves zontal assemblies 103 and then the tube is sheared to discreet lengths.

It will be understood that the instant apparatus is suitable for forming tubes with an overall diameter to wall or stock thickness ratio of approximately :1, or greater, up to a maximum wall or stock thickness of 11 gauge (.120").

All roll formulae calculations for generating the roll cross section or profile are based on the formed tube centerline at the point of exit of the last sizing station,

station 12,- with respect to the tube mall base 21 is constant for all tube O.D. sizes in order to facilitate straightening and cut-off operations, on a constant roller O.D. size at station 12 and that the tube is formed from its original fiat strip at a constant base line which has a definite relationship with the root diameter at station 7;

The root diameter at stations 12 of the rollers threof is larger than the root diameter at station 7 in order to maintain tension at all times on the welded tube. The root diameters are taken from the center of the roller to the bottom if its peripheral groove. 7

-It will be appreciated thatthe apparatus for manufacturing tubing from a flat strip stock does so by reverse bending. The primary object of this reverse bending is to initially form both ends of the strip into quarter circles in vertical roll stations 1 and 2. This is done so that both edges of the strip make a perfect 90 but seam when brought together as the tube is formed, without the need for initially scarfing the flat strip, along with increasing the speed and quality of the weld.

In the forming of the two quarter (90) circles at both ends of the strip in vertical roll stations 1 and 2, the center section is bent in a reversed direction. The reversed bent center section is subsequently reverse bent in the opposite direction, in vertical stations 3 and 4, thus forcing the two preformed quarter (90) circles to close in and begin to form a circle.

Horizontal rolls, stations 5 and 6 are used to complete the close in.

Vertical station 7 is the first of two seam guide stations, the function of which is to align and stabilize the tube seam through the forming and weld stations.

Horizontal roll station 8 reduces the seam gap from station 7.

Vertical roll station 9 is the second seam guide station, the function of which is the same as for station 7.

Stations 10 through 12 size the tube to its nominal O.D. after welding.

I claim:

1. In a tube forming mill, a plurality of serially arranged roller stations including a reverse bend station for progressively forming a tube from a strip of metal passed through said stations, said reverse bend station comprising companion female and a male roller, means for radially aligning said rollers and for mounting said rollers for rotation about parallel axes, said female roller comprising a convex central annular peripheral portion subtending an arc of substantially 80 and a pair of concavities laterally flanking said central portion, said concavities subtending arcs of between 90 and 100 and said male roller comprising a pair of peripheral annulii in alignment with respective concavities and spaced an axial distance at least equal to the axial width of said convex center portion and having peripheral surfaces radially complemental to the respective concavities and spaced therefrom a distance sufficient to form the lateral edge portions of the strip passed therebetween to conforming contours with said concavities and central portion, and further roller stations having rollers including means on the rollers for reversely bending the center portion of the strip and close in the lateral portions to form atube.

2. The invention according to claim 1 and said mill comprising a preforming station ahead of said reverse bend station and including female and male rollers of the general contour of the corresponding pair of rollers of said reverse bend station and the concavities in the female roller of the preforming station being shallower than the concavities of the corresponding roller of the reverse bend station, the" radius of curvature of the convex portion of the female roller of the preforming station being twice that of the convex portion of the female roller of the reverse bend station, and the radius of curvature of the convex portinon of the female roller of the reverse bend station being equal to the diameter of the tube at the bend line minus one-half of the thickness of the strip. a

3. The invention according to claim 2 and said female roller of said-preforming station comprising a pair of cylindrical rims outwardly of its concavities and having diameters substantially equal to the maximum diameter of the convex portion whereby a flat strip of material is caused to lay flat tangentially on said rims and the crest of said center portion.

4. In a tube forming mill according to claim 1 and said mill comprising a preforming station ahead of said reverse bend station and including female and male rollers of the general contour of the corresponding pair of rollers of said reverse bend station and the concavities in the female roller of the preforming station being shallower thanthe concavities of the corresponding roller of the reverse bend station, and the concavities in the female roller of the preforming station being about half as deep'as those in the corresponding roller of the reverse bend station.

5. The invention according to claim 4 and said female roller of the preforming station having side flanges flanking said rims and providing internal radial strip guiding surfaces.

6. The invention according to claim 1 and said means for mounting and radially aligning said rollers comprising a support having means for the fixed mounting thereof on an' associated base, a driven shaft mounted on said support, means holding said shaft on the support against endwise movement, means connecting one of the companion rollers to said shaft for rotation therewith .and holding the same against axial movement with respect thereto, a bore in said support parallel with the axis of rotation of said one companion roller, carrier mounted in said bore, roller and shaft element assembly including bearings rotatably mounted on said carrier on an axis parallel with said axis and 'held against endwise movement with respect thereto, and means adjustably connecting said carrier to the support for axial movement with respect thereto for aligning the roller carried via said shaft element from said carrier with the companion roller.

7. The invention according to claim -6 and said carrier having a bore and a counterbore at each end providing an outwardly facing shoulder, and said bearings having inner and outer races, and said shaft having an inwardly facing shoulder at one end engaging the outer edge of the inner race of the adjacent bearing while the outer race of the adjacent bearing is mounted in the adjacent counterbore and has an inner edge seated against the related outwardly facing shoulder, and the other of said bearings having an inner race sleeved on the shaft and having an outer race mounted in the other counterbore and having an inner edge seated against the outwardly facing shoulder in said other counterbore, and a nutthreaded on said shaft element and engaging the inner race of said other bearing and with said other bearing holding said shaft element against axial movement.

8. The invention according to claim 1 and said mill having a discharge end and having a strip inlet end and said rollers adjacent to the discharge end having root diameters larger than those of the rollers atthe strip inlet end thereof and imposing a tensile load upon the tube at it is formed from station to station.

4 9. The invention according to claim 1 and said concavities having a radius slightly larger than the radius of the finished tube whereby said tube is oversize before welding whereby after welding said tube is adapted to be sized down.

10. In a tube forming mill, a roller mounting structure comprising a support having a bore therethrough, a cylindrical carrier sleeve complementary mounted in the bore, a counterbore in each end of the sleeve presenting an outwardly facing shoulder therein, bearing at opposite ends of the sleeve each having an outer race fitted into the adjacent counterbore and seated against the shoulder therein each bearing having an inner race, a shaft having a shoulder at one end outwardly of the adjacent bearing in engagement with the inner race thereof, nut means threaded on the shaft engaging the inner race of the other bearing means and drawing said bearing means with said shaft tightly against said shoulders whereby said shaft and sleeve are relatively immovable axially, a roller fixed on said shaft for rotation therewith and held against axial movement With respect to the shaft, and means for locking the sleeve to the sup port in selected position.

11. The invention according to claim and seal means sleeved over the shaft and mounted on the support adjacent to the roller and means sealing the opposite end of the sleeve.

12. A mill for forming a tube from a flat strip of metal having an inlet end and an outlet end and a plurality of stations with forming rollers therebetween, means comprising a one-piece drive shaft for driving the rollers of a plurality of selected stations arranged in fixed spaced relation lengthwise of the driving shaft, each of said selected stations including a roller mounting driven shaft, each of said gear means including a gear with a sleeve telescoped on the drive shaft and positionable thereon axially thereof in adjusted position in driving alignment with the driven shaft of the respective station, and means for drivingly connecting the gear sleeve in adjusted position to the drive shaft, the rollers of the selected stations from the inlet to the outlet having increasing peripheral length to impose a tensile load on the strip, and clutch means between each driven shaft and the drive shaft.

13. In a mounting for journaling and axially adjusting a shaft assembly for a roller of a tube mill, a support, a single bore in said support, a one-piece, a complementally shaped carrier mounted in the bore for axial movement therein, a shaft assembly including bearings and a shaft connected thereto including means prevent ing relative endwise movement and mounted coaxially in the carrier via the bearings, means holding the bearings against axial movement with respect to the carrier where- 'by the carrier and shaft assembly are movable as a unit, said carrier comprising the pole support for said shaft assembly, and means adjustably connecting the carrier to the support for incremental axial movement with respect thereto and locking the carrier to the support in a selected position and a roller mounted on an end of said shaft.

14. The invention according to claim 4 and a third roller station disposed immediately after the reverse bend station and comprising an upper male roller having an annulus with a peripheral surface extending axially about 270 degrees and a lower female roller with a complemental groove mating with the annulus and spaced therefrom about the thickness of the strip of stock, said strip having its convex portion directed toward the annulus and straddling the groove whereby the stock upon pass- 10 ing through the third station being deformed into generally U-shape with an open top gap and curved sides,

a fourth station having an upper roller with an annulus having a peripheral edge of substantially degrees and a lower female roller with a complemental groove, the annulus engaging the top side of an area of the stock medially between said curved sides thereof and the groove underposed with respect to said area,

a fifth station having a pair of horizontally disposed rollers with grooves being segments of a common circle and engaging the sides of the stock issuing from the fourth station, and deforming the stock into a more rounded contour,

a sixth station having a pair of horizontal rollers with grooves as segments of a common circle of a diameter less than that of the previous station and engaging the sides of the stock and deforming it into a generally circular shape of a diameter of the circle of this station.

a seventh station having upper and lower rollers, the upper roller having an annulus extending into the gap at the upper side of the stock and said rollers having grooves of a common circle of a diameter less than the previous station and deforming the stock into smaller diameter than the sixth station,

an eighth station having a pair of horizontal rollers with grooves of smaller radius than the previous station and deforming the stock into a circular shape of less diameter than the previous station,

a ninth station having upper and lower rollers with grooves of a diameter less than the previous station and the upper roller having a thin annulus extending into the gap at the top of the stock, and the groove of the lower roller engaging the intermediate portion of the stock,

a tenth station comprising welding means for closing the gap and roller means having grooves of a radius to substantially close the gap, and

sizing stations beyond the tenth station having rollers with grooves of a desired diameter of the tube.

References Cited UNITED STATES PATENTS 1,141,066 5/1915 Lloyd 72-181 X 1,624,340 4/1927 Heinle 72181 2,176,115 10/1939 Yoder 72-1'81 2,306,945 12/1942 Hebron 72l81 X 2,416,865 3/1947 Bronander 72181 X 2,561,634 7/1951 Picton 72-181 2,563,214 8/1951 Croson 72-181 X 2,599,414 6/1952 Rodder 72247 X MILTON S. MEHR, Primary Examiner US. Cl. X.R. 

